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91.
To evaluate a novel elemental zinc bolus compared with a registered positive control zinc oxide bolus and assess serum zinc concentrations following concomitant treatment with a capsule containing copper oxide needles. Forty Romney-cross ewes were randomly allocated in a 2 × 2 factorial design study. On Day 0, 20 ewes received novel boluses containing elemental zinc (Investigational Veterinary Product, IVP) while 20 received a zinc oxide bolus (control; CP). Half the animals in each zinc treatment group (n = 10) were treated with a copper oxide needle capsule [Copasure® - Ewe]. Weekly, from Day −7 to 56, all ewes were assessed for signs of photosensitization, and for 10 ewes from each zinc treatment groups, samples were collected for analysis of serum GGT activity, serum zinc concentrations, faecal zinc concentrations and on Days −7 and 56, liver copper concentrations. Multivariable random-effects models assessed the effects of zinc treatment, copper treatment, treatment interactions and time on all analytes. Regression models examined associations between serum and faecal zinc concentrations and GGT activity. Low spore numbers indicated low Pithomyces chartarum challenge. Serum zinc levels were significantly higher in the IVP than in the CP group [p < 0.0001] and varied by time [p < 0.001] and positively associated with faecal zinc concentration [p < 0.001]. Copper treatment did not affect serum zinc [p = 0.82] or faecal zinc [p = 0.92] concentrations. Liver copper concentrations did not differ between zinc treatment groups on Day −7 [p = 0.6] or Day 56 [p = 0.95]. Only the CP/no copper group had no increase in liver copper concentrations.  相似文献   
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95.
MHC class I peptides as chemosensory signals in the vomeronasal organ   总被引:1,自引:0,他引:1  
The mammalian vomeronasal organ detects social information about gender, status, and individuality. The molecular cues carrying this information remain largely unknown. Here, we show that small peptides that serve as ligands for major histocompatibility complex (MHC) class I molecules function also as sensory stimuli for a subset of vomeronasal sensory neurons located in the basal Gao- and V2R receptor-expressing zone of the vomeronasal epithelium. In behaving mice, the same peptides function as individuality signals underlying mate recognition in the context of pregnancy block. MHC peptides constitute a previously unknown family of chemosensory stimuli by which MHC genotypic diversity can influence social behavior.  相似文献   
96.
ABSTRACT

Grain yield increases (responses) of canola (oilseed rape, Brassica napus L.) and spring wheat (Triticum aestivum L.) to application of nitrogen (N) and potassium (K) fertilizers were compared in the same experiment at eight field sites over three years (2000–2002) in southwestern Australia. Four rates of N (0–138 kg N/ha as urea) and four rates of K (0–60 kg K ha?1 as potassium chloride) were applied. Significant grain yield responses to applied N and K occurred for both crop species at all sites of the experiment, and the NxK interaction was significant. Canola required an average of 26% more applied N and 32% more applied K than wheat to produce 90% of the maximum grain yield. Applying increasing rates of K increased the rate of N required for 90% of maximum grain yield. Likewise, applying increasing rates of N increased the rate of K required for 90% of the maximum grain yield. Fertilizer K had no significant affect on the concentration of oil in canola grain or concentration of protein in both canola and wheat grain. Application of increasing rates of N decreased the concentration of oil while increasing the concentration of protein in canola grain, and increased concentration of protein in wheat grain. The NxK interaction was not significant for concentration of oil or protein in grain.  相似文献   
97.
β-glucan is a commonly researched plant cell wall component that when incorporated into food products has been associated with cholesterol and glycaemic response reductions. This study focusses on β-glucan rich fractions from barley and mushroom used in the production of extruded ready to eat snacks. Inclusion of barley β-glucan rich fractions and mushroom β-glucan fractions at 10 % levels increased the total dietary fibre content of extrudates compared to the control (P?<?0.05). Product expansion increased with the introduction of both barley and mushroom fraction (P?<?0.05) which in turn resulted in a reduction in product hardness (P?<?0.05). In vitro digestion protocol illustrated that inclusion of barley and mushroom β-glucan rich fractions manipulated the starch digestibility profile and hence rate of glucose release during digestion compared to the control sample. This in turn resulted in a significant (P?<?0.05) reduction in potential glycaemic response of the samples of between 20 and 25 % for barley β-glucan rich fractions and between 17 and 25 % for mushroom β-glucan rich fractions. We conclude that the inclusion of these fractions could be utilised by the food industry to manipulate the glycaemic response of extruded snack products.  相似文献   
98.
Investigation of the triclabendazole (TCBZ) resistance status of populations of Fasciola hepatica in field cases of fasciolosis, where treatment failure has been reported, can be supported by histological examination of flukes collected from recently treated hosts. In TCBZ-sensitive flukes (TCBZ-S) exposed to TCBZ metabolites for 1–4 days in vivo, but not in TCBZ-resistant flukes (TCBZ-R), morphological changes suggestive of apoptosis occur in cells undergoing meiosis or mitosis in the testis, ovary and vitelline follicles. In order to verify or refute the contention that efficacy of TCBZ treatment is associated with apoptosis in the reproductive organs of flukes, histological sections of TCBZ-S (Cullompton isolate) flukes and TCBZ-R (Sligo isolate) flukes were subjected to the TdT-mediated dUDP nick end labelling (TUNEL) in situ hybridisation method, a commercially available test specifically designed to label endonuclease-induced DNA strand breaks associated with apoptosis. Additionally, sections of in vivo-treated and untreated flukes originating from field outbreaks of suspected TCBZ-S and TCBZ-R fasciolosis were labelled by the TUNEL method. It was found that in treated TCBZ-S flukes, strong positive labelling indicating apoptosis was associated with morphologically abnormal cells undergoing mitosis or meiosis in the testis, ovary and vitelline follicles. Background labelling in the positive testis sections was attributed to heterophagy of cell debris by the sustentacular tissue. The triggering of apoptosis was probably related to failure of spindle formation at cell division, supporting the contention that TCBZ inhibits microtubule formation. In treated TCBZ-R (Sligo Type 1) flukes, and in treated flukes from field outbreaks of suspected TCBZ-R fasciolosis, no significant labelling was observed, while sections of fluke derived from a field case of fasciolosis where TCBZ resistance was not suspected were heavily labelled. Light labelling was associated with the testis of untreated Cullompton (TCBZ-S) and Sligo Type 2 (TCBZ-R) flukes, which exhibit abnormal spermatogenesis and spermiogenesis, respectively. This was attributed to apoptosis and to heterophagy of effete germ line cells by the sustentacular tissue. It is concluded that demonstration of apoptosis by in situ hybridisation using the TUNEL method on sections of 1–4 days in vivo TCBZ-treated F. hepatica can contribute to the diagnosis of TCBZ resistance in field outbreaks of fasciolosis.  相似文献   
99.
AIM: To evaluate and compare the effects of a variety of diets on the resistance of young, lightweight Merino lambs to repeated low-dose infections of Trichostrongylus colubriformis.

METHODS: Ninety-six 12-week-old lambs were fed balanced or unbalanced diets, and given primary (at 19 weeks of age) or both primary (at 12 weeks) and secondary (at 19 weeks) infections of T. colubriformis. Suboptimal diets were low in total intake, rumen undegradable protein, total protein, readily available carbohydrate or minerals, or supplemented with cod liver oil. Liveweight was monitored fortnightly, protection was assessed from worm counts at the end of the study (25 weeks) and faecal nematode egg counts (FEC) conducted weekly, and mast-cell response assessed at the conclusion of the study from concentration of mast-cell protease in the jejunum. Concentrations of glucose in plasma were measured at 21 weeks.

RESULTS: Diets unbalanced for total protein, readily available carbohydrate, Mo or cod liver oil each increased the worm counts after 6 weeks of secondary infection (at 25 weeks of age) and FEC during secondary infection. Low intake of a highnutrient diet restricted liveweight gain but did not affect the development of resistance, as indicated by worm counts and FEC. Defi ciency of available carbohydrate resulted in reduced liveweight gain and reduced concentration of glucose in plasma. There was a reduction in jejunal mast-cell protease concentration in sheep fed unbalanced rations.

CONCLUSIONS: The parasitology results and reduction in the concentration of jejunal mast-cell protease observed in sheep fed unbalanced rations suggest that the nutrient defi ciencies and the fi sh-oil supplement may have acted via inhibition or retardation of the host's acquired immune response. Diets unbalanced for a range of components adversely affected the acquired protective response to T. colubriformis to a similar extent and appeared to involve a similar mechanism as each other. The quality of the diet was more important than quantity for the development of resistance, and soluble carbohydrate was an essential component.  相似文献   
100.
Summary

The Brassicaceae (syn. Cruciferae) is an economically important botanical family providing a diverse range of foliar, root and seed crops for both human and domesticated animal consumption. However, in common with other plant species the Brassicacae have been endowed with the capacity to synthesize a range of antinutritional compounds, the most important of which are the glucosinolates, S-methylcysteine sulfoxide, tannins and erucic acid. In this review the adverse and possible beneficial effects of the inclusion of these compounds in human and animal diets are reviewed together with their chemistry, biosynthesis and methods for their analysis.  相似文献   
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